Method and system for binding halide-based contaminants

ABSTRACT

A method and apparatus are presented for reducing halide-based contamination within deposited titanium-based thin films. Halide adsorbing materials are utilized within the deposition chamber to remove halides, such as chlorine and chlorides, during the deposition process so that contamination of the titanium-based film is minimized. A method for regenerating the halide adsorbing material is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.13/858,644, filed Apr. 8, 2013, which is a divisional of U.S. patentapplication Ser. No. 13/541,435, filed Jul. 3, 2012, which is adivisional of U.S. patent application Ser. No. 13/041,227, filed Mar. 4,2011, now U.S. Pat. No. 8,216,377, which is a divisional of U.S. patentapplication Ser. No. 11/218,773, filed Sep. 1, 2005, now U.S. Pat. No.7,922,818, which is a divisional of U.S. patent application Ser. No.10/230,592, filed Aug. 29, 2002, now U.S. Pat. No. 7,311,942, which areall respectively incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This present invention relates generally to the field of integratedcircuit manufacturing technology and, more specifically, to thedeposition of titanium-containing films with low levels of chlorinecontamination.

2. Description of the Related Art

This section is intended to introduce the reader to aspects of the artthat may be related to various aspects of the present invention, whichare described and/or claimed below. This discussion is believed to behelpful in providing the reader with background information tofacilitate a better understanding of the various aspects of the presentinvention. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

In the manufacturing of integrated circuits, numerous microelectroniccircuits are simultaneously manufactured on a semiconductor substrate.These substrates are usually referred to as wafers. A typical wafer iscomprised of a number of different regions, known as die regions. Whenfabrication is complete, the wafer is cut along these die regions toform individual die. Each die contains at least one microelectroniccircuit, which is typically replicated on each die. One example of amicroelectronic circuit which can be fabricated in this way is a dynamicrandom access memory.

Although referred to as semiconductor devices, integrated circuits arein fact fabricated from numerous materials of varying electricalproperties. These materials include insulators or dielectrics, such assilicon dioxide, and conductors, such as aluminum, tungsten, copper, andtitanium in addition to semiconductors, such as silicon and germaniumarsenide. By utilizing these various materials, the various transistors,gates, diodes, vias, resistors, and connective paths comprising theintegrated circuit may be formed. Because of the complexity, both inmaterials and in design, incorporated into integrated circuits, theintegrated circuit can be designed to perform a variety of functionswithin a limited space.

In integrating the performance of the diverse materials and functionscomprising the semiconductor device, titanium-containing thin films orlayers are commonly employed for various purposes. For example, it isoften desirable to increase the conductivity between an enhanced, ordoped, region of the wafer and a subsequently deposited conductivelayer. One method of providing this increased conductivity involvesdepositing a thin titanium-containing film, such as titanium silicide,over the wafer so that it covers the enhanced region prior to depositionof the conductive layer.

Thin films of titanium-containing compounds have other uses as well inthe fabrication of integrated circuits. These uses include the use of athin layer of titanium nitride as a diffusion barrier to preventchemical attack of the substrate, as well as to provide a good adhesivesurface for the subsequent deposition of tungsten. In addition,titanium-containing thin films may be used to prevent interdiffusionbetween adjacent layers or to increase adhesion between adjacent layers.For example, thin films of titanium nitride, titanium silicide, andmetallic titanium can be deposited to facilitate adhesion and to reduceinterdiffusion between the layers of a semiconductor device. Othertitanium-containing films that may be useful for these or other purposesinclude titanium boride, titanium boronitride, titanium tungsten,tantalum nitride, and the ternary alloy composed of titanium, aluminum,and nitrogen.

The deposition of titanium-containing films is just one example of astep in the manufacture of semiconductor wafers. Indeed, any number ofthin films, insulators, semiconductors, and conductors may be depositedonto a wafer to fabricate an integrated circuit. Various depositionprocesses may be employed to deposit such thin films, but two commonprocesses are chemical vapor deposition (CVD) and atomic layerdeposition (ALD).

In CVD, the gas phase reduction of highly reactive chemicals under lowpressure results in very uniform thin films. A basic CVD process usedfor depositing titanium or titanium-containing films involves a givencomposition of reactant gases and a diluent which are injected into areactor containing one or more silicon wafers. The reactor is maintainedat selected pressures and temperatures sufficient to initiate a reactionbetween the reactant gases. Plasma may also be introduced to enhancesome deposition reactions, i.e. plasma enhanced CVD or PECVD. Thereaction results in the deposition of a thin film on the wafer. If thegases include hydrogen and a titanium precursor, such as titaniumtetrachloride, a titanium-containing film will be deposited. If, inaddition to hydrogen and the titanium precursor, the reactor contains asufficient quantity of nitrogen or a silane, the resultingtitanium-containing film will be titanium nitride and titanium siliciderespectively.

The ALD deposition process, also known as atomic layer chemical vapordeposition (ALCVD) is a refinement of the CVD process in which thedeposition of a layer of material is controlled by a pre-deposited layerof a precursor. Using the ALD technique, layers as thin as one moleculemay be deposited. The ALD technique provides complete step coverage andvery good conformality.

Both the CVD and ALD techniques are useful for depositingtitanium-containing thin films, typically using titanium tetrachlorideas a precursor. Use of titanium tetrachloride, however, has theundesired consequence of producing chlorine and chloride byproducts,i.e. Cl and/or HCl, which may contaminate the titanium-containing thinfilm. In addition, the reaction chamber walls are typically contaminatedby the chlorine-based byproducts. Because such byproducts are weaklybonded to the walls, the byproducts contaminate future reactions andproducts. This chlorine and chloride contamination is problematic sincechlorine is known to affect the performance of the resultingsemiconductor devices adversely either by impairing the functioning ofthe titanium-containing thin film or by poisoning or corroding adjacentmetal layers by diffusion of the chlorine contaminant. In addition, thechlorine-based byproducts may corrode the reaction chamber itself,further impairing future deposition reactions and increasing maintenancetime and costs associated with the chamber.

One current technique for reducing the degree of chlorine-basedcontamination is exposing the thin film to ammonia gas after deposition.This technique, however, does not remove all of the chlorine-basedcontamination from the thin film or from the reaction chamber andrequires the introduction of an additional process. Another currenttechnique for reducing chlorine-based contamination is to increase thedeposition temperature to greater than 350° C. This technique also doesnot remove all of the chlorine-based contamination from the thin film orfrom the chamber. Increased deposition temperature has the additionaldisadvantages of adversely affecting previously deposited films and ofproducing thin films with poor step coverage which can increase thefailure rates of the produced dies, i.e. higher deposition temperaturestypically reduce the yield of acceptable semiconductor devices. Ideally,a technique for reducing the degree of chlorine-based contamination willreduce contamination during the deposition process, not subsequently,and will operate within the preferred temperature range for thedeposition process.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the invention may become apparent upon reading thefollowing detailed description and upon reference to the drawings inwhich:

FIG. 1 illustrates a block diagram of an exemplary processor-baseddevice in accordance with the present technique;

FIG. 2 illustrates an exemplary memory sub-system in accordance with thepresent technique;

FIG. 3 illustrates an exemplary chemical vapor deposition or an atomiclayer deposition chamber incorporating removable liners in accordancewith the present technique;

FIG. 3 a illustrates a close-up view of the reaction chamber walls andthe removable liner of FIG. 3;

FIG. 4 depicts an exemplary corrugated removal liner in accordance withthe present technique;

FIG. 5 depicts an exemplary porous removable liner in accordance withthe present technique;

FIG. 6 depicts an exemplary mesh removable liner in accordance with thepresent technique;

FIG. 7 illustrates an exemplary chemical vapor deposition or atomiclayer deposition chamber utilizing an adsorptive coating in accordancewith the present technique; and

FIG. 7 a depicts a close-up view of the reaction chamber wall andadsorptive coating of FIG. 7.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

One or more specific embodiments of the present invention will bedescribed below. In an effort to provide a concise description of theseembodiments, not all features of an actual implementation are describedin the specification. It should be appreciated that in the developmentof any such actual implementation, as in any engineering or designproject, numerous implementation-specific decisions must be made toachieve the developers' specific goals, such as compliance withsystem-related and business-related constraints, which may vary from oneimplementation to another. Moreover, it should be appreciated that sucha development effort might be complex and time consuming, but wouldnevertheless be a routine undertaking of design, fabrication, andmanufacture for those of ordinary skill having the benefit of thisdisclosure.

Turning now to the drawings, and referring initially to FIG. 1, a blockdiagram depicting an exemplary processor-based system, generallydesignated by reference numeral 10, is illustrated. The system 10 may beany of a variety of types such as a computer, pager, cellular phone,personal organizer, control circuit, etc. In a typical processor-baseddevice, a processor 12, such as a microprocessor, controls theprocessing of system functions and requests in the system 10. Further,the processor 12 may comprise a plurality of processors which sharesystem control.

The system 10 typically includes a power supply 14. For instance, if thesystem 10 is a portable system, the power supply 14 may advantageouslyinclude permanent batteries, replaceable batteries, and/or rechargeablebatteries. The power supply 14 may also include an AC adapter, so thesystem 10 may be plugged into a wall outlet, for instance. The powersupply 14 may also include a DC adapter such that the system 10 may beplugged into a vehicle cigarette lighter, for instance.

Various other devices may be coupled to the processor 12 depending onthe functions that the system 10 performs. For instance, a userinterface 16 may be coupled to the processor 12. The user interface 16may include buttons, switches, a keyboard, a light pen, a joystick, amouse, and/or a voice recognition system, for instance. A display 18 mayalso be coupled to the processor 12. The display 18 may include an LCDdisplay, a CRT, LEDs, and/or an audio display, for example. Furthermore,an RF sub-system/baseband processor 20 may also be couple to theprocessor 12. The RF sub-system/baseband processor 20 may include anantenna that is coupled to an RF receiver and to an RF transmitter (notshown). A communications port 22 may also be coupled to the processor12. The communications port 22 may be adapted to be coupled to one ormore peripheral devices 24 such as a modem, a printer, a computer, or toa network, such as a local area network, remote area network, intranet,or the Internet, for instance.

The processor 12 controls the functioning of the system 10 byimplementing software programs. Generally, a memory sub-system, asdescribed below in regard to FIG. 2, is coupled to the processor 12 tostore and facilitate execution of various programs. For instance, theprocessor 12 may be coupled to the volatile memory 26 which may includeDynamic Random Access Memory (DRAM) and/or Static Random Access Memory(SRAM). The processor 12 may also be coupled to the non-volatile memory28. The non-volatile memory 28 may include a read-only memory (ROM),such as an EPROM, and/or flash memory to be used in conjunction with thevolatile memory or a high capacity memory such as a tape or disk drivememory. The size of the ROM is typically selected to be just largeenough to store any necessary operating system, application programs,and fixed data. The volatile memory 26 on the other hand, is typicallyquite large so that it can store dynamically loaded applications anddata.

A portion of the memory sub-system, such as the volatile memory 26, isdepicted in FIG. 2. Generally, a memory controller 30 is generallyprovided to facilitate access to the storage devices. While the presentembodiment illustrates the memory controller 30 as existing in thememory sub-system, the memory controller 30 may be in the processor 12or may exist in a completely separate chip, as can be appreciated bythose skilled in the art. The memory controller 30 may receive requeststo access the memory devices via one or more processors, such as theprocessor 12, via peripheral devices, such as the peripheral device 24,and/or via other systems. As previously discussed, the memory controller30 is generally tasked with facilitating the execution of the requeststo the memory devices and coordinating the exchange of information,including configuration information, to and from the memory devices.

The memory sub-system may include a plurality of slots or ranks 32A-32Hwhich are configured to operably couple a memory module, such as adual-inline memory module (DIMM), to the memory controller 30 via one ormore memory buses. Each DIMM generally includes a plurality of memorydevices such as DRAM devices capable of storing data. The memory busesmay include a memory data bus 34 to facilitate the exchange of databetween each memory device and the memory controller 30. The volatilememory 26 also includes a command bus 36 on which address informationsuch as command address (CA), row address select (RAS), column addressselect (CAS), write enable (WE), bank address (BA), and chip select(CS), for example, may be delivered for a corresponding request.

As one skilled in the art will recognize, various components of thesystem 10 and its associated memory sub-system, including the processor12, the non-volatile memory 28, and the volatile memory 26, incorporatenumerous semiconductor devices. These semiconductor devices, typicallydies fabricated by applying assorted deposition and etching processes toa silicon wafer substrate, rely upon the integrity and purity of theparticular layers of which they are composed to function properly. In agiven semiconductor device, one or more of the integral layers may be atitanium-containing thin film which functions to enhance conductivity,to prevent interdiffusion, to facilitate adhesion between layers of thesemiconductor device, etc. Impurities within the titanium-containingthin film may prevent the thin film from performing these functionsproperly and may thereby impair the functioning of the semiconductordevice.

Impurities within the thin film include the byproducts of the depositionreaction used to deposit the titanium-containing thin film, typicallychlorine and chloride. In particular, the titanium deposition reactioncommonly uses titanium tetrachloride, TiCl₄, as a precursor thatgenerates chlorine and chloride byproducts that contaminate both thetitanium-containing thin film and the reaction chamber itselfContamination of the reaction chamber allows for the contamination offuture reaction products. Using the exemplary technique described indetail below, a layer of titanium or titanium-containing film isdeposited upon a wafer such that chlorine and chloride contamination ofthe film and of the reaction chamber is significantly reduced.

To perform the deposition of the titanium-containing thin film, a CVD orALD reactor 40 is advantageously used, as illustrated in FIG. 3.Hydrogen and a titanium source gas, typically a titanium halide such astitanium tetrachloride, titanium tetrabromide, or titanium tetraiodide,are introduced into the reaction chamber 42 through a shower head 44. Ifdesired, a carrier gas, such as argon or helium, may be added to thereactant gases. The gases may or may not be pre-mixed. The gases aregenerally introduced through the shower head 44 to achieve gooddispersion of the gases, but the gases can be introduced by other means.

Desired reaction pressures are maintained by conventional pressurecontrol components, including a pressure sensor 46, a pressure switch48, an air operating vacuum valve 50, and a pressure control valve 52.The carrier gas and the byproduct gas given off during the reactionescapes from the reaction chamber 42 through an exhaust vent 54. Thesegases pass through a particulate filter 56, and gas removal may befacilitated by a roots blower 58.

In the reactor chamber 42, a substrate holder 60 is heated to atemperature of less than 700° C. In fact, temperatures may be in therange of 200 to 400° C., with pressures in the range of 0.1 to 6.0 Torr.Heating may be achieved through the use of halogen lamps 62, so that thesilicon wafer 64 is heated by convection. Plasma may also be introducedinto the reactor chamber 42 to enhance certain deposition reactions,i.e. PECVD, such as those reactions for depositing Ti or TiSi_(x).

As a result of this process, a chemical reaction occurs which results inthe deposition of a titanium-containing film along the exposed surfacesof the wafer 64. The thin films which are typically deposited by thisprocess are generally less than 3000 Å thick and generally depositedduring an exposure period greater than 200 seconds. In a depositionprocess where titanium tetrachloride is employed as the titaniumprecursor, the reaction can be characterized as TiCl₄+2(H₂)→Ti+4(HCl).As mentioned above, the titanium-based reaction may be modified toemploy other halides as the titanium source gas, such as titaniumtetrabromide or titanium tetraiodide, instead of titanium tetrachloride.The chemical reaction in those instances can be characterized asTiBr₄(or TiI₄)+2(H₂)→Ti+4(HBr) (or 4(HI)).

Optionally, a reducing agent can be introduced into the reaction chamber42 along with the titanium precursor and hydrogen. When this reducingagent is ammonia, the titanium-containing film which is deposited ontothe wafer 64 is composed principally of titanium nitride, and thereaction can be characterized by 6(TiCl₄)+8(NH₃)→6(TiN)+N₂+24(HCl) attemperatures between 400° C. and 700° C. When the reducing agent is asilane, the titanium containing film which is deposited onto the wafer64 is composed principally of elemental titanium and titanium silicide,and the reaction can be characterized by3(TiCl₄)+2(H₂)+2(SiH₄)→2(Ti)+TiSi₂+12(HCl). Various other titanium-basedreactions using similar titanium precursors will be known to thoseskilled in the art for depositing other titanium containing thin films,such as those comprising titanium boride and titanium boronitride.

While these assorted titanium-based reaction are effective fordepositing titanium-containing films, the byproducts of the depositionreactions, typically chlorides, such as HCl, and chlorine fromincomplete reactions, contaminate the deposited thin film. The resultingcontamination may compromise the effectiveness of thetitanium-containing thin film as a barrier or conductor, or the chlorineor chloride may diffuse out to contaminate layers adjacent to thetitanium-containing thin film. Either of these consequences ofcontamination may adversely affect the function of the semiconductordevice. Additionally the chlorine and chloride byproducts continue tocontaminate the reaction chamber 42 after the deposition reaction,thereby contaminating future deposition reactions and products.

To reduce or limit the effects of this chlorine-based contamination, itis therefore desirable to remove or adsorb the chlorine and chloridebyproducts during the deposition process to prevent the contamination ofthe thin layer product. To this end, it is desirable to include withinthe reaction chamber 42 a component composed of a material that has agreater affinity for chlorine and/or chlorides than thetitanium-containing thin film and those films comprising the remainderof the device. Such high affinity materials include, but are not limitedto carbon, silicon, manganese, group I or group II elements, amines(such as pyridine), phosphines, and other Lewis bases. Such anadsorptive component may thereby remove chlorine and/or chloride fromthe reaction area and thereby reduce the amount of chlorine and chloridecontamination. For instance, one possibility would be to construct orcoat a component of the reaction chamber 42, such as the shower head 44or the substrate holder 60, with such an adsorptive material. Thusconstructed or coated, the shower head 44 and substrate holder 60 areexamples of components of the reaction chamber 42 that may be referredto as solid material. Another possibility would be to dispose aremovable component or device composed of such a material within thereaction chamber 42. In some instances, the high affinity material, suchas manganese, carbon or silicon, may be heated to a temperature higherthan that of the reaction chamber 42 in order to increase the oxidationreaction rate of these materials with halogen byproducts, therebyenhancing their adsorption rate.

Referring once again to FIG. 3, such a removable component is depictedin the form of removable liners 66 secured to the walls 68 of thereaction chamber 42. Fasteners 70 may be employed to secure theremovable liners 66 and may be integral or separate from the walls 68 orthe removable liner 66 and may constitute hooks, clips, screws, or anyother type fastener capable of securing the removable liner 66 to thereaction chamber walls 68. A close-up of the association of theremovable liner 66, the fastener 70 and the reaction chamber wall 68 isshown in FIG. 3 a, representing the region of FIG. 3 outlined by thedotted line.

The removable liners 66 are at least partly composed of a material thathas a greater affinity for chlorine and/or chlorides than thetitanium-containing thin film and those films comprising the remainderof the device. For example, the removable liner 66 may be composed, atleast in part, of the carbon, silicon, manganese, group I or group IIelements, or amine These adsorptive materials, whether incorporated intoa removable liner 66 or a component of the reactor 40, act to pull thechlorine out of the gas phase, thereby reducing the amount of chlorineavailable to contaminate the titanium-containing thin layer. Wherecarbon, manganese or silicon is used as the removable liner 66 orcomponent of the reactor 40, these materials may be heated to atemperature greater than that of the reaction chamber in order toincrease their adsorption rate of chlorine or other halogens.

For example, if an amine, such as pyridine, is chemically bonded to thesurface of the removable liner 66, the amine will adsorb chlorides, suchas HCl, to form amine hydrochloride salts. The amine may be chemicallyattached to a substrate, such as a zeolite which will be the surface ofthe removable liner 66 or other component of the reactor 40. Carbon alsowill bind free chlorine and may comprise the removable liner 66 or aportion of the liner. Manganese may be used to coat the removable liner66 and will form stable halide with free chlorine. However, at thetemperatures and pressures typical of titanium-containing thin filmdeposition reactions, manganese does not react with chlorine.

One consideration in designing an adsorptive component, including theremovable liner 66, is that the component may be desired to providesufficient surface area to provide adsorption and removal of chlorineand chlorides for a useful time period. In the case of a removablecomponent, such as the liner 66, it may be desirable to be able to leavethe removable liner 66 in place within the reaction chamber 42 for aminimum of a week and preferably for a month or longer. Numerousconfigurations of the removable liner 66 may be employed to increase thesurface area of the removable liner 66 to provide the type of durationenvisioned. For example, referring now to FIG. 4, a corrugated liner 72is depicted which effectively increases surface area to lengthen theperiod that the removable liner 66 may be left in the reaction chamber42. The depth, pitch, number, and texture of the corrugations of thecorrugated liner 72 may be modified to increase its effective surfacearea. Alternately, referring now to FIG. 5, a porous liner 74 withperforations is depicted. The circumference, depth and number of thepores of the porous liner 74 may be adjusted to provide increasedeffective surface area. Referring now to FIG. 6, a mesh liner 76 isdepicted which also acts to increase the effective surface areapresented within the reaction chamber 42. The spacing, thickness, anddepth of the mesh of the mesh liner 76 may be modified to increase theeffective surface area of the removable liner 66. The removable liner66, corrugated liner 72, porous liner 74, and mesh liner 76 are examplesof solid material components of the reaction chamber 42.

As will be recognized by those skilled in the art, various othermodifications may be made to the removable liners 66 discussed above,i.e. corrugated, porous, and mesh, to increase their effective surfaceareas. Likewise other configurations of the removable liner 66 may beemployed which also provide an enhanced surface area. The discussion ofcorrugated, porous, and mesh configurations of the removable liner 66 ismerely demonstrative and is not intended as an exhaustive list ofpossible modifications for increasing surface area. Any removablecomponent performing the chlorine and/or chloride adsorptive functionsdescribed above may be used in the present technique, regardless ofwhether the surface area of such a component is increased or in whatmanner the surface area of such a component is increased.

An alternative to employing a removable liner 66 or other removablecomponent is depicted in FIG. 7. In FIG. 7, an adsorptive coating 78 isapplied to the interior wall 68 of the reaction chamber 42. Unlike theremovable liner 66, the adsorptive coating 78 is intended to remainwithin the chamber indefinitely. A close-up view of the adsorptivecoating 78 and its configuration with the reaction chamber wall 68 canbe seen in FIG. 7 a, representing the portion of FIG. 7 outlined by thedotted line. The adsorptive coating 78 may comprise the same materialsdiscussed above and may be applied so that it possesses a roughenedtexture to increase the available surface area for adsorption ofchlorine-based contaminants.

After a period of use, the removable liner 66, the adsorptive coating78, or any other adsorptive components employed may be regenerated torestore their adsorptive capacity. Such regeneration may include heatingthe removable liner 66, the adsorptive coating 78, or other component toa sufficiently high enough temperature to free chlorine-basedcontaminants, which may then be flushed out of the reaction chamber.Silicon based adsorptive materials, whether employed in a removableliner 66, an adsorptive coating 78, or another component, may beregenerated by etching off the titanium silicide or titanium nitridewhich will form on the silicon. By means of these regenerativeprocesses, the removable liner 66, the adsorptive coating 78, or theother adsorptive components may be used to reduce chlorine-basedcontamination for an extended period.

Use of these chlorine adsorptive components discussed above reduceschlorine and chloride contamination of the reaction chamber 42 and ofthe titanium-containing film product by one to two orders of magnitude.Prior to this technique, chlorine-based contamination levels might be ashigh as 10% chlorine in the deposited titanium-containing films and arenever less than 2% to 3% in the deposition temperature range of 200° C.to 350° C. Use of these adsorptive structures, however, reduceschlorine-based contamination to levels of 0.1% to 1% chlorine in atitanium-containing film deposited in the temperature range of 200° C.to 350° C. Further, use of these chlorine-adsorbing components shouldwork for any ALD or CVD based deposition of metal halides where a lowhalide content is desired in the deposited film. In other words, thematerials discussed above should attract other halides, such as fluorineas well as chlorine. Therefore, if reactant gases such as TaF₅ or WF₆are used, for example, the removable liner 66 or the adsorptive coating78 will attract fluorine or halide-based contaminants as well.

While the invention may be susceptible to various modifications andalternative forms, specific embodiments have been shown by way ofexample in the drawings and will be described in detail herein. However,it should be understood that the invention is not intended to be limitedto the particular forms disclosed. Rather, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the invention as defined by the following appended claims.

What is claimed is:
 1. A semiconductor circuit comprising: atitanium-based film having a halide-based contaminant content of lessthan 1% due to adsorption of the halide-based contaminants by a materialhaving a greater affinity for the halide-based contaminants than thetitanium-based film.
 2. The semiconductor of claim 1, wherein the halideis chlorine.
 3. The semiconductor of claim 1, wherein the halide isiodine.
 4. The semiconductor of claim 1, wherein the halide is bromine.5. The semiconductor of claim 1, wherein the titanium-based film istitanium.
 6. The semiconductor of claim 1, wherein the titanium-basedfilm is titanium nitride.
 7. The semiconductor of claim 1, wherein thetitanium-based film is titanium silicide.
 8. The semiconductor of claim1, wherein the titanium-based film is titanium boride.
 9. Thesemiconductor of claim 1, wherein the titanium-based film has between0.1% and 1.0% chlorine-based contamination.
 10. The semiconductor ofclaim 1, wherein the material comprises manganese.
 11. A methodcomprising, regenerating a material that has adsorbed halide-basedcontaminant due to an affinity for the halide-based contaminant that issufficiently greater than that of a titanium-based film for asemiconductor circuit to limit a halide-based contaminant content of thetitanium-based film, wherein regenerating comprises heating a depositionchamber in which the material is disposed until the halide-basedcontaminant is released.
 12. The method of claim 11, whereinregenerating the material comprises regenerating a chlorine-adsorbingmaterial by heating the chlorine-adsorbing material to release adsorbedchlorine.
 13. The method of claim 11, wherein regenerating the materialcomprises regenerating a chloride-adsorbing material by heating thechloride-adsorbing material to release adsorbed chlorides or theirconstituent elements.
 14. The method of claim 11, comprising adsorbingthe halide-based contaminant in the deposition chamber with the materialsuch that the halide-based contaminant content of the titanium-basedfilm is limited to less than 1%.
 15. A system, comprising: a depositionchamber; a semiconductor circuit disposed within the deposition chamber;a material disposed within the deposition chamber; a titanium-based filmof the semiconductor circuit, wherein the titanium-based film comprisesa halide-based contaminants content of less than 1% due to adsorption ofthe halide-based contaminants by the material, wherein the material hasa greater affinity for the halide-based contaminants than thetitanium-based film.
 16. The system of claim 15, wherein the materialthat has the greater affinity for the halide-based contaminants than thetitanium-based film is a solid material.
 17. The system of claim 15,wherein a shower head within the deposition chamber comprises thematerial that has the greater affinity for the halide-based contaminantsthan the titanium-based film.
 18. The system of claim 15, wherein thematerial comprises manganese.
 19. The system of claim 15, comprisinghydrogen and a titanium source gas within the deposition chamber. 20.The system of claim 15, wherein the titanium-based film has between 0.1%and 1.0% chlorine-based contamination.